1. Field of the Invention
The present invention relates to a pattern width measuring apparatus, a pattern width measuring method, and an electron beam exposure apparatus. More particularly, the present invention relates to a pattern width measuring apparatus, a pattern width measuring method, and an electron beam exposure apparatus for measuring pattern width of a pattern formed on the wafer by an electron beam.
2. Description of the Related Art
With the miniaturization of semiconductor devices in recent years, it has been very important to measure pattern width when manufacturing the semiconductor devices. Therefore, there is proposed a method for measuring pattern width by scanning the pattern with an electron beam using SEM (Scanning Electron Microscope), and detecting edges of the pattern from change of the quantity of secondary electrons generated by the electron beam irradiation. (cf. Y. Furuya et al, “Model S-6000 Field Emission CD Measurement SEM”, abstract of the 93rd workshop of the 132nd Committee (Electron and Ion Beam Science and Technology) of Japan Society for the Promotion of Science, Nov. 8, 1985, pp. 1–5; M. Miyoshi et al, “topographic contrast in scanning electron microscope during CD measurement”, abstract of the 93rd workshop of the 132nd Committee (Electron and Ion Beam Science and Technology) of Japan Society for the Promotion of Science, Nov. 8, 1985, pp. 109–114)
However, it has been very difficult to precisely detect edges of patterns of the highly miniaturized semiconductor device of these days by the conventional measuring method of the pattern width.